1. Field of the Invention
The present invention relates to a photosensitive material processor, and more particularly to a processing solution supplying apparatus of a photosensitive material processor for supplying processing solutions such as working solutions and replenishing solutions to processing tanks of the photosensitive material processor such as an automatic processor.
2. Description of the Related Art
An automatic processor for automatically developing, fixing, washing and drying a photosensitive material is provided with a developing tank in which a developer is stored, a fixing tank in which a fixer is stored, and the like. Working solutions such as a developer and a fixer are supplied to the developing tank and the fixing tank when the automatic processor is initially used. In addition, since the developer undergoes a decline in its developing capability due to the processing of the photosensitive material and oxidation by oxygen in the air, and the fixer is consumed in the processing of the photosensitive material and by being discharged as attached to the photosensitive material processed, replenishing solutions are supplied to the developing tank and the fixing tank so as to recover the processing capabilities of the solutions and maintain the levels of the solutions to fixed levels.
To supply these working solutions and replenishing solutions, as disclosed in Japanese Patent Application Laid-Open Publication No. 52343/1990, it has been proposed to prepare the working solutions and replenishing solutions by mixing a stock solution and a dilution liquid in respective mixing tanks immediately before being supplied to the processing tanks and to supply them to the respective tanks. With this technique, in a case where the stock solution and the dilution liquid are supplied to the mixing tank at the time of initial use of the automatic processor or replacement of the solution, a stock solution supplying pump and a dilution liquid supplying pump are operated simultaneously, and the two pumps are respectively stopped after the lapse of an operating period set in advance for each tank at a predetermined ratio.
Meanwhile, the developing tank and the fixing tank are respectively provided with a circulating system comprising a circulating pipeline, a circulating pump, and a heat exchanger. The temperatures of the developer in the developing tank and the fixer in the fixing tank are controlled to fixed levels as the solutions are being circulated by these circulating systems. The aforementioned mixing tanks are respectively made to communicate with a portion of the circulating pipeline upstream of the circulating pump via a supply pipeline. Accordingly, when the automatic processor is initially used or the solution is replaced, the processing solution prepared in the mixing tank is supplied to the developing tank or the fixing tank by its own weight via the supply pipeline until a solution level in the developing tank or the fixing tank becomes identical with the solution level in a storage portion.
With the above-described technique, however, when the automatic processor is initially used or the solution is replaced, the processing solution is supplied to an empty processing tank, so that there are cases where air remains in the circulating system. For this reason, if the circulating pump is operated at the time of starting the processing of the photosensitive material, there are cases where the air is discharged at a stretch into the developer in the developing tank or the fixer in the fixing tank, thereby causing the developer or the fixer to scatter or enter another tank. In addition, after the air is quickly vented, the solution level declines, making it impossible to detect an accurate solution level. With respect to the mixing tank, meanwhile, there are cases where the residual air causes the processing solution not to be properly supplied to the supply pipeline or causes the processing solution to overflow from the mixing tank, or the solution is scattered when the air is vented from the mixing tank.